Conditioned storage chamber



1942. G. B. PIRNIE v CONDITIONED STORAGE CHAMBER Filed Oct. 24, 1938IINVENTOR. 650961.: B. P/PN/i BY ATTQRNEY Patented Dec. 15, 1942 IUNITED STATES PATENT OFFICE CONDITIONEDSTORAGE CHAMBER George B. Pirnie,Center Point, Iowa Application October 24, 1938, Serial No. 236,710

2 Claims.

Thisinvention relates to produce storage and display cases and hasparticular relation to means for controlling the temperature andmoisture content ofproduce stored in such cases.

One of the main objects of my invention is to provide a display case forfresh produce in which the temperature and the humidity may bereadilycontrolled and in which the produce is readily accessible and in plainView of the customer at all times.

It is another object of my invention to provide a device of thischaracter in which produce of various kinds may be segregated inseparate compartments to permit the humidity in each compartment to bemaintained at a point best suited for the particular produce.

Still another object of my invention is the provision of a simple andeifective but relatively inexpensive means for cooling the inside of adisplay case with air from the out-of-doors during cold weather.

Other and further features and objects of the invention will be moreapparent to those skilled in the art upon a consideration of theaccompanying drawing and following specifications, wherein is disclosedan exemplary embodiment of the invention, with the understanding,however, that such changes may be made therein as fall within the scopeof the appended claims, without departing from the spirit of theinvention.

In said drawing the figure is a view in perspective showing a displaycase adapted to be cooled by outside air. Part of the case has beenbroken away for better illustration of the device.

A large number of vegetables, including Irish potatoes, cabbage,carrots, turnips, lettuce, celery, apples, lemons, etc., do not requirea very close regulation of the temperature, but it is preferable thatthey be kept relatively cold. However, it is necessary that evaporationfrom their surfaces be kept down to a minimum. To do this, it ispreferable that the produce be kept in a closed space to permit thecontrol of humidity and also to permit the produce to be kept out ofdirect contact with the chilled air or other medium used in cooling.

I have shown in the figure a preferred embodiment of my invention inwhich cold outside air may be drawn into an insulated container duringthe cold months of the year to keep in proper condition the fruits andvegetables displayed in airtight display cases above the coolingchamber.

This device includes a closely fitted box or case indicated generally at80, said case having insulated side walls and fioor.

A plurality of vegetable or fruit display boxes, indicated generally at90, are supported upon the upper edges of the cooling case. Each of thedisplay cases is preferably comprised of a sheet metal box approximately10 inches in depth, 18 inches wide by 24 inches long. The top of eachsheet metal box is attached to a wooden framework 92 in which glassdoors 93 and 94 are adapted to slide. It is necessary that these slidingdoors be a very close fit within the side portions of the frame in orderto prevent the escape of moisture from the box and to retain the coldconducted through the sides and bottoms of the boxes from the coolingcase below.

These display boxes are adapted to permit a high humidity to be carriedby the air surrounding the edibles, while at the same time leaving themexposed to View. A source of moisture is supplied within each box andpreferably comprises a can of water with a wick.

The entire structure disclosed in the figure makes it possible tomaintain the produce in a state of high humidity while at the same timefurnishing an economical means for maintaining a relatively lowtemperature. I

These display cases in themselves serve to keep both fruits andvegetables in good condition for a much longer period of time thanpossible out in the open store room, the action of the case beingdependent mainly upon the high humidity maintained, and the coolingeffect I secure.

As explained before, however, a great many commodities will be kept inbetter condition if they are kept in a cold as well as moist atmosphere.

It is, of course, possible to supply artificial cooling in the summertime, in order to make my device usable the entire year. Any suitablemeans may be employed to remove heat from the interior of the case.

The wooden frames 92 of the individual display cases are constructed soas to extend several inches beyond the sides of the sheet metal boxes9|, the overhanging edges permitting the cases to be supported upon theupper edges of the cooling case.

The boxes are placed so as to permit air to freely circulate around allof the sides and the bottoms of all the boxes. A conduit 8i is attachedto an opening in oneend of the cooling case to conduct air into the casefrom the outof-doors. A small exhaust blower 82, powered by an electricmotor 83, is located at the opposite end of the case.

As the exhaust blower 82 is energized, a slight vacuum will be createdwithin the case 80 and cool air will be drawn into the conduit 8| fromthe outside.

The blower 82 may be controlled by the thermostat 86 located within thecase, and may be arranged to shut off the blower when sufficient coolair has been drawn into the case.

A weighted flapper valve 84 is pivotally mounted within the intakeconduit 8| and arranged to close by gravity when the blower is not inoperation to prevent the entry of cold air when not required.

In order that the cool air within the case may be thoroughly distributedand come in contact with the walls and bottoms of all of the displaycases, a small vertically directed propeller type fan 8'! is mountedclose to the floor of the case. This fan is preferably operated inparallel with the blower 82. A switch 88 is provided to permit bothblowers to be completely disconnected if desired. A door 89 is providedat the end of the case to permit access to the interior and also topermit cooling apparatus to be installed in the cooling cabinets ifdesired during the Warm weather.

When it is desired that thedisplay case be cooled by artificial means,the entire cooling unit may be inserted through the door 88 of thedisplay cabinet. I

It is apparent that a device constructed in accordance with my inventionconstitutes a simple and inexpensive means for supplying the properconditions to preserve fruits and vegetables, especially during coolweather. I have, however, adapted the device for all-year-around use byproviding for the use of an auxiliary cooling apparatus.

Although I have shown and described certain specific embodiments of myinvention, it is apparent that modifications thereof may be made bythose skilled in the art. Such modifications may be made withoutdeparting from. the spirit and scope of my invention as set forth in theappended claims.

I claim as my invention:

1. In a display case for produce, a means for conditioning the producecomprising a plurality of relatively airtight boxes, each having a glasstop, metal sides and bottom, an insulating cabinet having an open top,said boxes supported upon and sealed against the open top thereof, aconduit means connected with the cabinet and forming an intake for cooloutside air, an exhaust means comprising a blower also connected withthe cabinet and adapted to draw cool air into the cabinet through theintake conduit, through the cabinet and exhaust it to the out-ofdoors,and a means within the cabinet to cause air within the cabinet to wipeall the side and bottom surfaces of the boxes.

2. In a produce display case, a means for utilizing cold outside airduring cool weather comprising an intake conduit adapted to carryoutside air into the case, an exhaust fan adapted to exhaust air fromthe case to the outside,'a weighted flapper valve on the intake conduitadapted to close when the exhaust fan is not in operation, means withinthe display case to cause a thorough distribution of the air within thecase, and a thermostatic means within the case to control the exhaustfan in accordance with the temperature of the air within the case.

GEORGE B. PIRNIE.

